PCI: Allocate 64-bit BARs above 4G when possible
Try to allocate space for 64-bit BARs above 4G first, to preserve the space
below 4G for 32-bit BARs. If there's no space above 4G available, fall
back to allocating anywhere.
[bhelgaas: reworked starting from http://lkml.kernel.org/r/1387485843-17403-2-git-send-email-yinghai@kernel.org]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index c30baae..86fb8ec 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -102,6 +102,8 @@
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
static struct pci_bus_region pci_64_bit = {0,
(dma_addr_t) 0xffffffffffffffffULL};
+static struct pci_bus_region pci_high = {(dma_addr_t) 0x100000000ULL,
+ (dma_addr_t) 0xffffffffffffffffULL};
#endif
/*
@@ -198,8 +200,7 @@
* alignment and type, try to find an acceptable resource allocation
* for a specific device resource.
*/
-int
-pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
+int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
resource_size_t size, resource_size_t align,
resource_size_t min, unsigned int type_mask,
resource_size_t (*alignf)(void *,
@@ -209,10 +210,19 @@
void *alignf_data)
{
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
- if (res->flags & IORESOURCE_MEM_64)
+ int rc;
+
+ if (res->flags & IORESOURCE_MEM_64) {
+ rc = pci_bus_alloc_from_region(bus, res, size, align, min,
+ type_mask, alignf, alignf_data,
+ &pci_high);
+ if (rc == 0)
+ return 0;
+
return pci_bus_alloc_from_region(bus, res, size, align, min,
type_mask, alignf, alignf_data,
&pci_64_bit);
+ }
#endif
return pci_bus_alloc_from_region(bus, res, size, align, min,